Tolerance, the thymus, and suppressor T cells
Waksman, B.H.
Clinical and Experimental Immunology 28(3): 363-374
1977
ISSN/ISBN: 0009-9104 PMID: 70289 Document Number: 111708
The interrelationships among tolerance, the thymus and suppressor T cells are discussed in this review. The nonspecific suppressor-cell system may play many in vivo roles. The most apparent, but perhaps least important biologically, would be its role in competition of antigens, depression of immunological responses during graft-vs.-host reactions, and feedback suppression after intense stimulation. A 2nd would be its role in the early phase of tolerance induction to exogenous antigens. More important might be its role holding back responses to autoantigens in young individuals until the specific tolerance mechanism is fully developed and has acted to remove these from the danger list. Perhaps equally important in a negative way is the role of this system in chronic intracellular and other infections, in which nonspecific suppression results from continuous exposure to antigen and paves the way for specific tolerance to the same or other antigens and for failure of the host's resistance mechanisms. The system may play a similar negative role as an introducer of specific tolerance to tumors. Conversely, since both chronic infections and tumors progress from low dose to high dose situations, it may ultimately prove that specific tolerance precedes the state of nonspecific suppression in some or all cases.